Construction of the piers that will support the new St. Croix River bridge will begin next spring, a year earlier than planned, the Minnesota and Wisconsin transportation departments said Monday.

The $50 million contract will open for bids yet this year or early in 2013, MnDOT said.

Previously, construction was planned to begin in spring 2014.

Findings from tests of bedrock strength in the river bottom are being reviewed "to make the project more efficient in terms of managing scope, schedule and budget," said Jon Chiglo, MnDOT's project director.

"By separating out the foundation work, we can start construction sooner, reduce inflation costs and create jobs a year earlier than scheduled."

Chiglo said last month that eliminating one set of piers on the new bridge will save millions of dollars. Building five pier sets in the river, two legs to a set, also will help boat navigation and improve the bridge's appearance, he said.

The new four-lane bridge will replace the 81-year-old Stillwater Lift Bridge and connect expressways in Oak Park Heights and St. Joseph Township, Wis.

The project will add trails, including the conversion of the Lift Bridge into a bicycle and pedestrian crossing. It also includes constructing three miles of four-lane road on Hwy. 35 in Wisconsin, and reconstructing about three miles of Hwys. 36 and 95 in Minnesota.

Also next spring, work will begin on a new interchange where the bridge will touch land at Hwy. 95, and on reconstruction of frontage roads along Hwy. 36. Removal of a long-vacated Oak Park Heights neighborhood could begin in the spring, as well.

Major work on the stretch of Hwy. 36 through Oak Park Heights will begin in 2014. MnDOT wants to move historic Shoddy Mill from the path of the bridge to the riverfront south of Stillwater yet this fall.

The bridge is expected to cost between $280 million and $310 million. The total cost for the project is estimated at between $580 million and $676 million.

The mayor of a traditionally liberal Wisconsin city has ordered the removal of a cemetery's monuments to Confederate soldiers, saying the Civil War was "a defense of the deplorable practice of slavery" and "an act of insurrection and treason."